Assuming about 300 bottles per barrel–I think you did the same–it does appear to be a raw increase of $2-$5 per bottle. But that would all be capital tied up in wine that won’t see the light of day for several years. I think it’s reasonable to expect some return on investment after putting all that money into barrels.
It will be interesting to see what happens as economics encourage producers to try different, less cost-intensive methods. Small barrels are not the only container out there that imparts toasted oak flavor and allows a small degree of oxygenation. And aside from that, it seems like CA is often just following Bdx thinking with oak regimes. Maybe the answer is not to mimic the French, but to pursue different styles altogether.